BIAB Efficiency Calculation

[doug293cz]

@doug293cz

We seem to utilize the same calcs from Kai for extract. I was curious and tested your sheet against my own and it was a dead ringer.

Yes, I did my spreadsheet after studying Kai's web pages. It's an independent implementation, but is based on the same process model.

PricelessBrewing used the math in my spreadsheet to set up his on-line calculator, but later simplified the formulas (less rigorous, but very small error.)

Brew on

 

[Big Monk]

Yes, I did my spreadsheet after studying Kai's web pages. It's an independent implementation, but is based on the same process model.

Brew on

Mine as well. One thing i love about Excel is the Solver. one of the things I've incorporated that make is essential as a troubleshooter tool:

The "Conversion\Extraction" Efficiency Solver Macro:

This button allows you to set the ratio of Actual versus First Wort Extract by changing the "Conversion/Extraction" (a.k.a. First Wort) Efficiency value.

 

[doug293cz]

Recirculation is also a very useful helper in achieving higher extraction, faster and more stable conversion, etc.

Yes, recirculation during the mash can speed up conversion, thus allowing more complete conversion with shorter mash times, and less chance of having all the amylase denatured before conversion is complete. But, once you get to 100% conversion efficiency, there is nothing you can do to increase it further. The only way to "beat the chart" in my previous post is to do a good fly sparge, which can give you a few percent better lauter efficiency than a triple batch sparge.

Brew on

 

[Big Monk]

Yes, recirculation during the mash can speed up conversion, thus allowing more complete conversion with shorter mash times, and less chance of having all the amylase denatured before conversion is complete. But, once you get to 100% conversion efficiency, there is nothing you can do to increase it further. The only way to "beat the chart" in my previous post is to do a good fly sparge, which can give you a few percent better lauter efficiency than a triple batch sparge.

Brew on

I don't believe 100% Conversion/Extraction Efficiency is possible.

You can Convert 100% of the available starches to sugars but you can't Extract 100% of the possible sugars from the grain. That's why I feel "Conversion Efficiency" is a confusing term. Should be "First Wort Efficiency". You'd be hard pressed to see anyone breaking the 95% threshold here.

Note: I have trouble with my naming conventions in my own sheets. It's difficult to break out variables with their own names, particularly efficiency terms because you run out of names fast!

 

[doug293cz]

Mine as well. One thing i love about Excel is the Solver. one of the things I've incorporated that make is essential as a troubleshooter tool:

The "Conversion\Extraction" Efficiency Solver Macro:

View attachment 697570

This button allows you to set the ratio of Actual versus First Wort Extract by changing the "Conversion/Extraction" (a.k.a. First Wort) Efficiency value.

I didn't set mine up with a macro to do that. I just use "Goal Seek" to match calculated OG (or pre-boil SG) to actual measured OG by adjusting the "Conversion Efficiency" input cell. There are a lot of interesting things you can back calculate using Goal Seek

Brew on

 

[doug293cz]

I don't believe 100% Conversion/Extraction Efficiency is possible.

You can Convert 100% of the available starches to sugars but you can't Extract 100% of the possible sugars from the grain. That's why I feel "Conversion Efficiency" is a confusing term. Should be "First Wort Efficiency". You'd be hard pressed to see anyone breaking the 95% threshold here.

That's why I don't consider conversion efficiency and extraction efficiency to be synonyms. I follow the terminology used by BrewSmith and Brewers Friend.

Conversion efficiency equals the percentage of potential extract in the grain that is actually created in the mash.

Lauter efficiency equals the percentage of extract created in the mash that makes it into the boil kettle.

Mash efficiency equals the percentage of potential extract that makes it into the boil kettle. Mash efficiency = conversion efficiency * lauter efficiency.

Extract is the sugar, soluble proteins, (and all other dissolved material) that comes from the grain.

Based on the definition of the word extraction, "extraction efficiency" could plausibly be used to describe mash efficiency or lauter efficiency. So, I prefer not to use that term.

"First wort" sounds equivalent to the wort in the mash just prior to the start of lautering (unless you still have gradients at the start of lautering.) It is indeed possible to get 100% first wort efficiency, according to this definition, and it is equivalent to conversion efficiency.

Brew on

 

[Big Monk]

That's why I don't consider conversion efficiency and extraction efficiency to be synonyms. I follow the terminology used by BrewSmith and Brewers Friend.

Conversion efficiency equals the percentage of potential extract in the grain that is actually created in the mash.

Lauter efficiency equals the percentage of extract created in the mash that makes it into the boil kettle.

Mash efficiency equals the percentage of potential extract that makes it into the boil kettle. Mash efficiency = conversion efficiency * lauter efficiency.

Extract is the sugar, soluble proteins, (and all other dissolved material) that comes from the grain.

Based on the definition of the word extraction, "extraction efficiency" could plausibly be used to describe mash efficiency or lauter efficiency. So, I prefer not to use that term.

"First wort" sounds equivalent to the wort in the mash just prior to the start of lautering (unless you still have gradients at the start of lautering.) It is indeed possible to get 100% first wort efficiency, according to this definition, and it is equivalent to conversion efficiency.

Brew on

This could quickly devolve into a semantic battle but let’s just say I’m not sure I agree that your definition (and BF and BS) of Conversion Efficiency can equal 1 in any practical sense.

It would imply that dividing maximum potential gravity by actual gravity equals 1, or conversely that actual gravity equals the maximum potential gravity.

I could be looking at this incorrectly, of course.

 

[doug293cz]

This could quickly devolve into a semantic battle but let’s just say I’m not sure I agree that your definition (and BF and BS) of Conversion Efficiency can equal 1 in any practical sense.

It would imply that dividing maximum potential gravity by actual gravity equals 1, or conversely that actual gravity equals the maximum potential gravity.

I could be looking at this incorrectly, of course.

Maximum potential gravity is defined by the actual SG obtained in a Congress Mash (dry basis, fine grind.) So, by definition a Congress Mash attains 100% conversion efficiency. Ordinary brewers can also attain 100% conversion efficiency with suitable mash conditions.

Brew on

 

[LittleRiver]

[86%ish]......Is that a good efficiency for biab or I need to find holes in my method or technique....

I've always been intrigued by climbing. Even as a young child I thoroughly enjoyed the simple act of scrambling on top of a rock. I don't know why, it was just part of me. As a teenager I was drawn to climbing bigger rock faces, always with a child like fascination with them. I just enjoyed the feel of the rock in my hands, and the way I felt as I moved over the stone. Climbing a particularly aesthetic line, linking natural features up a cliff, placing only removable anchors that didn't alter the rock, was pure joy.

Somewhere along the way, rock climbing became a numbers game to most. They were striving to achieve the highest difficulty number possible. Many started drilling holes for expansion bolt anchors, and even chipping edges and drilling pockets where they wished holds would be. It seemed to me they had lost the soul of climbing just to achieve a higher number. Climbing gyms started popping up, where you pull on plastic holds bolted to artificial walls, always with the goal of climbing the highest difficulty number.

I agree with you, that's a bunch of ******** rambling that's only marginally relevant to the discussion at hand.

My point is don't let chasing numbers distract you from what is important. A beer that tastes good is good.

 

[Big Monk]

Maximum potential gravity is defined by the actual SG obtained in a Congress Mash (dry basis, fine grind.) So, by definition a Congress Mash attains 100% conversion efficiency. Ordinary brewers can also attain 100% conversion efficiency with suitable mash conditions.

Brew on

I guess maybe that’s my hang up. I could never achieve 100% because I would never finely grind my malt or squeeze extract from my mash tun liner. (EDIT: see Vikeman’s response below to explain strikethroughs)

In this case it seems it’s just methods outside my SOP, i.e. I’d rather stick with lower efficiency and keep a coarser crush/not squeeze. The ends don’t justify the means IMHO.

Glad we cleared that up!

 

[VikeMan]

I guess maybe that’s my hang up. I could never achieve 100% because I would never finely grind my malt or squeeze extract from my mash tun liner.

I believe @doug293cz speaks of 100% efficiency only in the context of conversion of starches to non-starches (his conversion efficiency, your first wort efficiency). So squeezing (or not) doesn't enter into it at that point.

 

[Big Monk]

My point is don't let chasing numbers distract you from what is important. A beer that tastes good is good.

Right. It’s really extract quality that matters, not quantity.

 

[Big Monk]

I believe @doug293cz speaks of 100% efficiency only in the context of conversion of starches to non-starches (his conversion efficiency, your first wort efficiency). So squeezing (or not) doesn't enter into it at that point.

True. I misspoke there.

More to the point: I can’t bring myself to finely grind my grist, especially because of my constant recirculating preference. Not to mention other mash related factors. So, 100% “whatever you want to call it” efficiency is not in the cards for me.

 

[VikeMan]

My point is don't let chasing numbers distract you from what is important. A beer that tastes good is good.

I couldn't agree more, if by chasing numbers you mean shooting for higher and higher efficiency, rather than reasonably accurately predicting gravities and volumes using a dialed-in process.

 

[VikeMan]

I can’t bring myself to finely grind my first, especially because of my constant recirculating preference. Not to mention other mash related factors. So, 100% “whatever you want to call it” efficiency is not in the cards for me.

Personally, I believe (can't really prove, obviously) that I get a cleaner malt flavor from a moderate crush than a super-fine crush. Plus, I don't do BIAB, so an all flour grist wouldn't work for me anyway.

 

[doug293cz]

I guess maybe that’s my hang up. I could never achieve 100% because I would never finely grind my malt or squeeze extract from my mash tun liner. (EDIT: see Vikeman’s response below to explain strikethroughs)

In this case it seems it’s just methods outside my SOP, i.e. I’d rather stick with lower efficiency and keep a coarser crush/not squeeze. The ends don’t justify the means IMHO.

Glad we cleared that up!

Nothing wrong with that. Life is a series of compromises in just about every aspect. Everyone must make their own compromises based on the criteria that are more or less important to them. Efficiency for efficiency's sake only makes sense for large scale commercial brewing. For homebrewing, having a consistent (and therefore predictable) process is much more important (for most brewers.)

The writing I do about efficiency is primarily to help brewers understand what affects efficiency, how to rigorously calculate it (if interested), and assist brewers in diagnosing exceptionally low efficiency.

Brew on

 

[Big Monk]

Nothing wrong with that. Life is a series of compromises in just about every aspect. Everyone must make their own compromises based on the criteria that are more or less important to them. Efficiency for efficiency's sake only makes sense for large scale commercial brewing. For homebrewing, having a consistent (and therefore predictable) process is much more important (for most brewers.)

The writing I do about efficiency is primarily to help brewers understand what affects efficiency, how to rigorously calculate it (if interested), and assist brewers in diagnosing exceptionally low efficiency.

Brew on

I agree. It’s much of what I try to help with also. Troubleshooting pH and efficiency are my side hobbies.

 

[HBearBrew]

This chart shows the highest possible lauter efficiencies (and thus the highest possible mash efficiencies) available for a couple of different grain absorption rates, and four different counts of batch sparge steps (including none.) Since mash efficiency equals conversion efficiency times lauter efficiency, mash efficiency will always be less than or equal to lauter efficiency. You should target as close to 100% conversion efficiency as you can (you appear to be there already with your first BIAB.)

View attachment 697568

Brew on

Thanks @doug293cz for this very helpful chart. Your explanations, together with this article (Declining Extract Efficiency at Higher Original Gravities) and the corresponding chart (extract efficiency) helped me finally understand why my efficiency varies, and how to accurately plot it. I have read Kai's webpages, and went back to John Palmer's chap 19. It has a very useful table for BIAB expected extract efficiency.

I do BIAB no sparge - not the most efficient approach of course, but quite predictable at the end and that's good enough for me

Based on all these readings, I was able to put together a quick calculator for expected efficiency, see the excel table in the compressed file attached. It is based on one's system, so you need to write down in the table the water to grist ratio and efficiency of several batches for the calculator to be able to plot the expected efficiency. I used kg and l in my example, but it can be as easily used with pounds and gallons, as long as one is consistent with the unit used.

Thanks for the inspiration